![Page 1: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/1.jpg)
CNSpathologyThirdyearmedicalstudents
DrHeyamAwad2018
Lecture1:anintroduction
![Page 2: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/2.jpg)
CNScourse
• Thisisa7hourcourseandthetopicscoveredareimportantforyourclinicalyearsandyourworkasadoctorinanyspecialityyouchoose.Pleasegiveittheimportanceitdeserves.• Wesynchronisedthelectures’topicsbetweenalldisciplines(mainlyanatomy,physiologyandpathology)soyoucanunderstandsubjectsfullyandeasilyandweminimisedrepetitionoftopicsbetweendisciplines.• Isentthecoursesyllabus,ILOSandlecturedistribution.Pleasehavealookatthesetofamiliariseyourselfwiththecourse.• Pleasenotethefacultyisbeingverystrictwithattendancepolicy,makesureyoudon'tputyourselfintotrouble;wewillnotbeabletohelpyouwiththis.
![Page 3: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/3.jpg)
Pathologylectures
• Asusualwewillhavetwosetsofslides;oneasapresentation,andadetailedslideforthecontentofthelectures.• Thedetailedslideswillcontainalltheinformationyouneedfortheexam.• AtthebeginningofeachslideIwilllistthelearningoutcomesofthelecture,attheendIwillputasummaryofthemainpointsyouneedtoconcentrateonaswellaspracticequestionstocheckyourunderstandingandtoknowwhattoexpectintheexam.• Theslideswillbeavailableonyourwebsiteandthetheelearningbeforethelectureday.
![Page 4: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/4.jpg)
Lecture1:introductionILOS• AquickrevisionoftheCNSstructureincludingbrainlobesandsomeoftheirfunctions• Tounderstandtheasymmetrybetweentherightandlefthemispheres,withexamples.• Toknowthestructureandfunctionofneuronsandglialcells• Tounderstandhowneuronsandglialcellsrespondtoinjury.• Toapplytheaboveknowledgeinunderstandingbraindiseases
![Page 5: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/5.jpg)
CNS
• TheCNSiscomposedofthebrainandthespinalcord.• Itsmainfunctionistoreceiveinformation,coordinateitandsendappropriatecommandstotherestofthebody.• CNSiscomposedofwhiteandgreymatter.• Thewhitematteriscomposedofmyelinatedaxons(myelincomposedofcellmembranesofoligodendrocytes).• Thegreymatteriscomposedoftheneuronesofthecortexandcertainnuclei.
![Page 6: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/6.jpg)
Brainlobesthebrainiscomposedoffouranatomicallobes:frontal,occipital,temporalandparietallobes.
![Page 7: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/7.jpg)
![Page 8: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/8.jpg)
Cerebralcortex1.frontallobe• Containstheprimarymotorcortex:performsfinalcorticalmotorprocessing• Broca’sareaintheleftfrontallobecontrolsmotor patternofspeech,ifdamaged=expressivedysphasia=thepersonknowswhathewantstosaybutcannotexpressthem.
![Page 9: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/9.jpg)
![Page 10: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/10.jpg)
2.Temporallobe
• Importantforcomplexprocessingofsensoryinput• ContainsWernicke'sarea:auditory,visualandsomaticassociationscoalesceinthisarea.• Ifdamaged:inabilitytounderstandspokenorwrittenlanguage.(receptivedysphasia)
![Page 11: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/11.jpg)
ThereareassociationsbetweenBroca’sandWernicke’sareas
![Page 12: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/12.jpg)
3.Parietallobe
• Containshighordersensoryareas• Containsareafornamingobjects• Containsareaforprocessingofvisuallanguage=reading
![Page 13: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/13.jpg)
4.Occipitallobe:Containsthevisualcortex
![Page 14: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/14.jpg)
Brainasymmetry
![Page 15: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/15.jpg)
Whyunderstandingbrainasymmetryisimportant?• Samediseaseprocessescanhavedifferentconsequencesaccordingtothesideaffected• Example:astrokeaffectingtheBroca’sareaintheleftfrontallobecanresultinexpressivedysphasia.Similarlesioninthemirrorimageareaintherightsidemightresultinnosymptomsatall.
![Page 16: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/16.jpg)
BRAINCELLS
• TheCNScontains100billionneurons.• Italsocontains10-50timesthisnumberofglialcells.• 40%ofourgenesparticipateintheformationoftheCNS.
![Page 17: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/17.jpg)
neuron
• IstheprincipalfunctionalunitoftheCNS.• Theyreceiveandtransmitinformation• Matureneuronscannotdivide:theyarepermanentcells• However,neuralprogenitorsarefoundinthebrainandcandivide…..???ExpansionofthesecanhelppatientswithCNSdiseases(thisisanareaofactiveresearch)
![Page 18: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/18.jpg)
Neuralprogenitors
• Neuralprogenitorsarecellsthatarecapableofdividingalimitednumberoftimesandhavethecapacitytodifferentiateintoarestrictednumberofneuronalandglialcelltypes.• Zikavirusinfectionisassociatedwithmicrocephaly,probablythroughinfectingneuralprogenitorscausingtheirdeathandresultingindecreasedbraingrowthinembryos.
![Page 19: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/19.jpg)
ZIKAVIRUS
• Basedonasystematicreviewoftheliteratureupto30May2016,WHOhasconcludedthatZikavirusinfectionduringpregnancyisacauseofcongenitalbrainabnormalities,includingmicrocephaly.itisthoughtthatthevirusdoessobyinfectingprogenitorcells.
![Page 20: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/20.jpg)
Basicstructureofneurons.
![Page 21: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/21.jpg)
Neuronscomeinseveralshapes!
![Page 22: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/22.jpg)
GLIALcells= ةیقبدایالخ
• Aresupportivecells4types:1. Astrocytes2. Oligodendrocytes3. Microglialcells4. Ependymalcells
![Page 23: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/23.jpg)
Astrocytes= ةیمجنایالخ
• givestructuralsupporttoneurons• controlneuralbiochemicalenvironment.• Astrocyteprocessesareassociatedwiththebloodvesselstoformthebloodbrainbarrier
![Page 24: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/24.jpg)
Astrocytes
![Page 25: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/25.jpg)
Oligodendrocytes= نصغتلاةلیلقةیقبد
• Oligodendrocytesformthemyelinsheathwhichsurroundsaxonsandisimportantforfasttransmissionofactionpotentialbysalutatoryconduction
![Page 26: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/26.jpg)
Microglialcells= ةریغصلاةیقبدلاایالخلا
• Microglia:bloodderivedmacrophages
![Page 27: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/27.jpg)
Ependymalcells ةیبصعلاةناطبلاایالخ =
• Theylinetheventricleandthespinalcord.
![Page 28: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/28.jpg)
![Page 29: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/29.jpg)
ReactionofneuronstoACUTE injury
• Acute neuronalinjuryformsredneurons• redneutronsresultusuallyduetoacuteinjuryduetohypoxiaorischemia.• redneuronistheearliestmorphologicmanifestationofneuronalcelldeath• Appearafter12-24hoursofirreversible injury• Characterisedmicroscopicallybyshrinkageofcellbody,pyknosis,disappearanceofthenucleolusandLossofNisslsubstance(seenextslidefordefinition)• lossofNisslsubstanceresultsinintensecytoplasmiceosinophilia
![Page 30: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/30.jpg)
• Nisslsubstance:largegranularsubstancefoundinneurons.Thesegranules areofroughendoplasmicreticulum(RER)withrosettesoffreeribosomes,andarethesiteofproteinsynthesis.
![Page 31: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/31.jpg)
Redneurons
![Page 32: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/32.jpg)
Redneurons
![Page 33: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/33.jpg)
Subacuteandchronicneuronalinjury
• =degeneration• Neuronaldeathduetoprogressivedisease• Example:inAlzheimer• Celllossaffectingfunctionally relatedneurons(notnecessarilystructurallyrelated)
-Neuronaldeathusuallyisapoptoticdeathandisassociatedwithreactivegliosis.
![Page 34: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/34.jpg)
GLIOSIS
• Gliosis isanonspecific reactivechangeofglialcellsinresponsetodamagetoCNS.Inmostcases,gliosis involvestheproliferation&/orhypertrophyofseveraldifferenttypesofglialcells,includingastrocytes,microglia,andoligodendrocytes.
• SO:GLIALCELLSCANPROLIFERATEANDDIVIDEINRESPONSETOINJURY.
![Page 35: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/35.jpg)
Gliosissimplymeansincreasedglialcellsthinkofitascounterpartoffibrosisintherestofthebody
![Page 36: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/36.jpg)
Reactionofastrocytestoinjury
• Astrocytesaretheprinciplecellsresponsibleforrepairandscarformation=gliosis• Reactiveastrocytesduringrepairundergochanges=gemistocyticastrocyte.
![Page 37: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/37.jpg)
repair
• Astrocytesarethemaincellsresponsibleforrepairandscarformation(gliosis).• Injurycausesthefollowingchangesinastrocytes:• 1.hypertrophyandhyperplasiainastrocytes.• 2.enlargednuclei• 3.prominentnucleoli.• 4.increasedpinkcytoplasm.• 5.increased,ramifyingprocessesThesechangesinastrocytes:gemistocyticastrocyte.
![Page 38: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/38.jpg)
gemistocytes
![Page 39: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/39.jpg)
Gemistocytes
![Page 40: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/40.jpg)
ReactionsofMicrogliatoInjury
• Microgliaaremesoderm-derivedphagocyticcellsthatserveastheresidentmacrophagesoftheCNS.• Theyrespondtoinjuryby(1)proliferating;(2)developingelongatednuclei(rodcells) (3)formingaggregatesaroundsmallfocioftissuenecrosis(microglialnodules);or(4)congregatingaroundcellbodiesofdyingneurons(neuronophagia).• Inadditiontoresidentmicroglia,blood-derivedmacrophagesmayalsobepresentininflammatoryfoci.
![Page 41: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/41.jpg)
Microglialnodules..youcanthinkoftheseasgranulomas=aggregatesofmicrogliawhicharebasicallymacrophages.
![Page 42: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/42.jpg)
Rodcells
![Page 43: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/43.jpg)
ExamquestionAllofthefollowingstatementsarecorrectaboutthecellsseeninthispictureexcept:
A.originatefromastrocytes
B.indicatethestartofarepairprocessafterinjury
C.canbeseenaroundareasofdemyelination.
D.cellsoforiginarepermanentcells
E.canbeseeninthevicinityofresolvedinfarction.
![Page 44: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/44.jpg)
Answertopreviousquestion
• D..becausegemistocytesoriginatefromastrocyteswhichareglialcellsandunlikeneurones,glialcellsdodivide;theyaren'tpermanent• therestofthechoicesareobviouslycorrect.Notethegemistocytescanbearesponsetoanyformofinjurysothechoicesaboutdemyelinationandoldinfarctarecorrect.
![Page 45: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/45.jpg)
Examstylequestion
• A27yearoldfemaleunderwentacaesariansectionduringwhichshehadmassivebleeding.Hersystolicbloodpressuredroppedto45.Thebleedingcontinuedandshedied13hoursaftertheoperation.Ifyouweretodotheautopsyexamyouwouldexpecttoseewhichofthefollowingchangesinherneurons• A.cytoplasmicbasophilia• B.Prominentnucleoli• C.cellswelling• D.pyknosis• E.Gliosis
![Page 46: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/46.jpg)
Explanationofthequestion
• Thescenariohereisaboutacuteischemicdamage.the13hourperiodmeanthatthemorphologicchangeshavedeveloped.Rememberthatredneuronesarethefirstmorphologicmanifestationofischemicdamageandtheyneed12hourstodevelop.• ObviouslytheonlycorrectchoiceisD,therestarewrongandglossiswrongbecauseit’snotaneuronaldamageandisnotanacutechange.
![Page 47: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/47.jpg)
Afinalnote
• theexamquestionswillbesimilartothequestionsintheexamplesabove,andsomewillbeclinicallyoriented..soyouknowwhattoexpect.
• Foryourinformation:thewordneuroneiswrittenwithane attheend(British)orwithoutane (Americanstyle)
![Page 48: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/48.jpg)
SUMMARY1/3• CNScellsareoftwotypes:neuronesthatarethefunctionalunitsandglialcellswhicharesupportive.glialcellsaremuchmoreabundant.• Glialarefourtypes:• 1.astrocytesthataresupportive,controlthemicroenvironment,formpartofthebloodbrainbarrierandareresponsibleforgloss(fibrosisandscarringofCNS).• 2.Oligodendrocytes:theircellmembranesformmyelinsheathimportantforinsulatingnerveimpulsesthusmakingtransmissionquicker• 3.Ependymalcells,linetheventriclesandspinalcordcavity.SpecialisedependymalformchoroidplexusthatsecretesCSF• 4.MicrogliaarespecialisedresidentmacrophagesimportantforinflammatoryandimmunologicreactionofCNS.
![Page 49: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/49.jpg)
SUMMARY2/3
• Neuronesrespondtoacute injurybychangingtored neutrons.theyappear12hoursafterirreversibleinsultandcharacterisedbycytoplasmicshrinkageandincreasedeosinophilia(duetolossofNisslsubstance),pyknosis,lossofnucleolusandincreasedramifyingprocesses.• subacuteorchronicneuronalinjurycausesdegenerationanddeathofneurones,usuallybyapoptosis(todecreaseriskofdamaginginflammation).• chronicneuronalinjuryusuallyaffectsfunctionallyrelated neurones
![Page 50: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/50.jpg)
SUMMARY3/3
• glialcellsarelessvulnerabletoacuteinjuryandrespondduringrepairprocessandgliosisformation.• Astrocytesarethemaincellsinvolvedinrepairandrespondbyforminggemistocytes:hypertophiccellswithlargeeosinophiliccytoplasm,largenucleiandprominentnucleoli• glialcellscanproliferatewhileneuronescannot(althoughneuronalprogenitorshavealimitedcapacitytodivide)• Microgliarespondtoinjuryby:hyperplasia,rodcells,neurophagiaandmicroglialnoduleformations.
![Page 51: CNS pathology Third year medical students...Pathology lectures • As usual we will have two sets of slides; one as a presentation, and a detailed slide for the content of the lectures](https://reader033.vdocuments.site/reader033/viewer/2022042011/5e7218d87d44d52ff332874d/html5/thumbnails/51.jpg)